The Foreign Office declined to comment on whether it was planning to close the embassy.

"We'll make any announcement about our embassy and staffing levels at the appropriate time," the spokesman said.

Western diplomatic sources told AFP earlier that Britain was evacuating all its diplomatic staff from Iran after the storming of two British compounds in Tehran by protesters angry at new sanctions against Iran over its nuclear programme.

The incident has provoked international condemnation, including a strongly worded statement from the UN Security Council.